Bearing and locking means for mounting drive shafts, and for securing hammer mill rotors against displacement on drive shafts



APPE; 'l

.linie l1, 1954A, M'. 11Hl r v BEARING AND LOCKINGMEANS -FoR MOUNT-INGlDRIVE SHAFTS, AND 'FOR'SECURING'HAMMER- MILDRoToRs. AGAINSTDISPLACEMENToN DRIVE sl-xARTs-v I INVENTOR ff Meh/n J. 'Hdppe ATTORNEY Patented June1, 1,954

BEARING AND LOCKING MEANS FOR MOUNTING DRIVE SHAFTS, AND FOR SECURINGHAMMER MILL ROTORS AGANST DISPLACEMENT ON DRIVE SHA '.lSv

Melvin J. Happe, New Holland, Pa., assignor to The New Holland MachineDivision of The Sperry Corporation, New Holland, Pa., a corporation ofDelaware Application January 2, 1952, serial No. 264,592

Claims. (Cl. 241-191) This invention relates to a locking means forsecuring a driven element against rotational and axial displacement on adrive shaft, and particularly to such locking means which is adapted forincorporation in the shaft bearing means.

It is a primary object of the invention to provide such locking means ormechanism w-hich avoids any necessity for mutilating or weakening of thedrive shaft as by slotting for the reception of a key, or as is oftencaused by the use of set screws and the like. Such an arrangementconstitutes an advantageous and economical simplification as compared toprior arrangements tor the same general purpose, and due to avoidance ofany mutilating or weakening of the shaft, permits the use of arelatively smaller and weaker shaft in many cases than might otherwisebe required.

It is a further object to provide such a locking means which mayadvantageously be incorporated in a bearing structure, whereby assemblyof the driven element and shaft with the bearing structure will alsoserve to assemblethe drive shaft and the locking means in operativerelation.

It is also an object to provide such an arrangement in which the lockingmeans serves to fixedly axially position the bearings and driven elementinl proper predetermined relation on the shaft, and in addition locksthe driven element against rotation relative to the shaft. In additionthe invention permits a wide range of axial adjustment of the severalparts on the drive shaft.

It is a still further object to provide such a locking arrangement whichfunctions automatically to increase the looking grip thereof on theshaft in response to increased loads or forces on the driven elementtending to cause slippage.

The foregoing as well as other incidental objects and advantages areattained by the preferred embodiment of the invention illustrated inthe' accompanying drawing, in which:

Figure 1 represents a front elevation, partly in section, of a hammermill rotor and supporting shaft structure embodying my invention;

Figure 2, a section on the line 2 2 of Figure 1, looking in thedirection of the arrows;

Figure 3, an enlarged diagrammatic view similar to Figure 2 but showingthe several parts in relatively unlocked position, at'the commencementof the assembling operation, and in dotted lines showing the severalparts Vafter they have vbeen relatively rotated into locked position.

.Referring now in detail to the accompanying drawings, the referencecharacter 2 designates suitable angle iron or other frame members whichserve as a means for supporting the relatively axially spaced bearings3. Rotatably supported in the bearings 3, is a horizontal drive shaft 4of usual round cross section, which carries any usual driven element,generally designated 5 for rotation therewith. In the presentembodiment, the invention is illustrated as applied to a usual hammermillv rotor structure, such as is generally disclosed in the patent toPaul C. Dellinger et al. No. 2,276,940, of March 17, 1942. To this end,the driven element 5 is illustrated in the form of a hammer mill rotorwhich may comprise a plurality of plates B having central perforatonsreceiving the shaft 4, the plates 6 being maintained in spaced radialplanes on the shaft by means such as the tubular spacers l' interposedbetween each adjacent pair of plates 6 on the shaft.

In order to secure the several parts of the rotor structure againstrelative rotary movement, I employ a plurality of bolts 8 extendingaxially through the several plates 6 and passing between opposed sets ofrelatively spaced lugs or bosses 19 formed ohn each of the tubularspacers or shaft sections l. While'only the front or forwardly presentedbolt 8 is shown in Figure l, it will be appreciated that a similarlyarranged bolt 8 is disposed in sunilar manner on the rear side of therotor structure shown. Suitable hammers I0 may be pivotally carriedadjacent the outer periphery of the rotor structure, as by means of therods or pivotal elements H extending through the respective platesadjacent their outer edge portions. The bearings 3, which are preferablyidentical, each comprises an annular outer'race l2 and an inner race orrace sleeve i3, a series of usual roller balls lli being operativelydisposed between these races I2 and I3 in usual manner. Axial movementof the outer race i 2 is limited by engagement thereof with the shoulderl5 of the bearing block or housing. Preferably the bearing structurealso includes a conventional dust seal I6 and lubricating tting l1communieating with the interior of the bearing housing.

Preferably the inner ball race sleeve i3 is employed as one of thecooperating locking elements of the invention. To. this end, the sleevei3 includes'V an axially projecting end portion having an external,preferably cylindrical, cam V surface 2l)v eccentric to theibore whichreceives the Vshaft 4, as will be readilyapparent from onefof theFigures l, 2 or 3 of the drawings. I

A, cooperatingfcam element such as-the collar 2l welded or 'otherwisefixed to and VVVcarried by the rotor is also formed with a cam ,suriace22 which is preferably cylindrical and also eccentric to the axis of theshaft 4. In this instance the cam face 22 constitutes the inner surfaceor face of a blind cylindrical bore extending into the end of the collar2l. The bore 22 is sufficiently larger than the eccentric cam portion Zof the sleeve i3 as to freely loosely receive the cam portion 26 and topermit a partial rotation of said portion 213 as indicated in Figure 3,so that the coaction of the two cam surfaces 2i! and 22 responsive torelative rotary movement thereof will urge their respective members i3and 2i in opposite transverse directions into i'irm locking engagementwith the shaft d.

In order to assemble such a. structure, the two bearings 3-3 and therotor may all be slid into position axially along the shaft l, thebearings being disposed on opposite sides of the rotor and closelyadjacent thereto, whereupon the bearing sleeves i3 respectively may bemanually positioned to bring their eccentric portions 22 respectivelyinto concentric registering relation with the eccentric sockets or bores2s in the collars or cam elements 2i of the rotor 5. The bearings maythen be moved axially to dispose the cam portions 2d in their respectivesockets 22, whereupon the bearing housings may be then secured in fixedposition on their respective supporting frame members 2. At this stage,the shaft 4 still remains freely axially slideable through the otherassembled parts and may be easily manually adjusted to any desired axialposition. When the desired position is reached, each set of cooperatingbearing collar 2i and bearing sleeve i3 are partially rotated relativeto each, as indicated by the arrow A in Figure 3, so that the inwardlydirected cam face of the collar 2l is moved relative to the cam surface2G, from a position concentric thereto as indicated in full lines inFigure 3, to the position indicated in dotted lines in said gure,wherein the cam surfaces of the two cam elements i3 and 24 respectivelytend to urge these two members transversely in opposite directionsacross the axis of the shaft 'i and thus into frictional grippingengagement on opposite sides of A the shaft 4.

Preferably the direction of rotation of the rotor 5 utilised to causethe locking engagement of the two cam elements i3 and 2i with the shaft4, as indicated by the arrow A in Figure 3, is in a direction oppositeto that in which the shaft 4 and rotor 5 will normally rotate inoperation. In such event, it will be seen that the inertia of the rotord will in itself tend to tighten or increase the locking action as therotation of the shaft is commenced, and as loads are imposed on therotor 5 during operation these will tend to increase the lockingengagement automatically in accordance with the amount of load orresistance to rotation imposed on the rotor.

From the foregoing it will be understood that the locking means of theinvention serves to xedly axially position the bearings and drivenelement or rotor 5 in proper predetermined relation on the shaft d, andin addition locks the driven element against rotation relative to theshaft.

While it is not essential that the cam portion or element 2G be formedas an integral part of or connected to the bearing sleeve i3 as in thepreferred embodiment of the invention, but same may in some instances beformed as a separate and entirely independent locking element, it willbe apparent that its incorporation as a part of the bearing structurepermits simultaneous assembly of both the bearing and the locking meanson the shaft d as a part of the same operation.

In this application I have shown and described only the preferredembodiment of my invention as by law required. However, I recognize thatthe invention is capable of other and different embodiments, and thatthe several details may be varied in different respects, all withoutdeparting from the invention; therefore the drawings and descriptionherein are to be construed as merely illustrative in nature and not asexclusive.

Having thus described my invention I claim;

l. A self-locking bearing for a hammer mill comprising a drive shaft andrelatively axially spaced bearings rotatably supporting said shaft, eachsaid bearing including an outer annular ball race and an inner ball racesleeve, said sleeve having a bore therethrough coaxially receiving saidshaft and an axially projecting end having an external cylindricalsurface eccentric to said bore, and a hammer mill rotor coaxiallymounted on said shaft between said sleeves, collars fixedly carried bysaid rotor, each having a counterbore eccentric to said drive shaftloosely receiving one of said eccentric cylindrical surfaces, wherebyrelative rotary movement between said rotor and said sleeves and theresulting cam action between said sleeves and said collars will jam saidsleeves and said collars respectively into locking relation againstopposite sides of the shaft.

2. The combination defined in claim 1, in which the said eccentriccounterbore of each said collar is blind, and the end of each saidsleeve abuts against the end of its respective counterbore to resistaxial thrusting forces tending to urge the shaft toward either of saidbearings, such thrusting forces being transmitted through the sleevesand balls to their respective outer ball races.

3. The combination comprising a bearing, a drive shaft rotatablysupported in said bearing, said bearing including an outer ball race, aninner rotatable ball race sleeve, and balls operatively disposed betweensaid races and said sleeve, said sleeve being formed with an axial borereceiving said drive shaft, a hammer mill rotor coaxially mounted onsaid shaft adjacent said sleeve, and cooperating cam elements carried bysaid sleeve and said rotor respectively to jam said sleeve and saidrotor transversely into frictional locking engagement with oppositesides of said shaft.

4. The combination comprising a drive shaft, a bearing sleeve coaxiallyrotatably receiving said shaft, a driven element normally freelyrotatable on said shaft, said element being of substantially greaterdiameter and having a substantially greater rotational inertia than saidbearing sleeve, and interengaging radially presented cam surfacesfixedly carried by said sleeve and said element respectivelyeccentrically to said shaft, whereby relative rotation between saidsurfaces will urge said sleeve and said element in opposite diametricdirections into binding engagement with said shaft, the difference ininertia between said sleeve and said element tending to produce suchrelative rotation and binding engagement responsive to changes inrotational speed of the shaft.

5. The combination comprising a shaft, a hammer mill rotor rotatablethereon, a cam element fixed to said rotor and having a cam surfaceeccentric to said shaft, a cooperating cam element journalled on saidshaft having a cam surface eccentric to said shaft in operativeengagement with the cam surface of said rst cam element, wherebyrelative rotary movement of said cam elements about said shaft willcause said elements to bind against said shaft in opposite diametricaldirections, whereby the said rotor may be caused to rotate with saidshaft, such binding being increased responsive to increased loads onsaid rotor tending to rotate it and the cam element :Fixed theretorelative to said cooperating cam element.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Name Date Searles Nov. 10, 1925 Ammon May 21, 1929 Searles Feb.`17, 1942 Johnston July 22, 1947 FOREIGN PATENTS Country Date France Oct.27, 1931

